Joe,
Looks like you opened the door on an issue I dealt with a few years ago, that being the lack of 6.5 mm bullet moulds on the market. Given that other than the 6.5 TCU, there really aren't any small cased 6.5s around, meaning anything smaller than 6.5MS or Jap or Carcano and most of those rifles were throated for long 156-160 grain bullets, most cast bullets moulds for them run 140-160 grains. I looked into all my sources and other than some antique Lyman moulds in the 90-120 grain range, most 6.5 moulds out there are 140 grains and up. You'll also note the RCBS and Lyman don't even offer 6.5 designs. I think that you are going to have to have a custom mould made if you are interested in pursuing cast bullets in your 6.5 TCU.
A friend of mine made up a wildcat 6.5 using a 357 max case, which is really very similar to 6.5 TCU with a rim. He had same issues as you and had to have a custom mould made. His was made by NEI and ran between 110 and 120 grains with different alloys. I think you will have to do the same.
regards from underway...not at trail glades,
Graycg